Combined mold and clamp for stringed musical instruments



Sept. 27, 1932. JOHNSON 1,879,288

COMBINED MOLD AND CLAMP FOR STRINGED MUSICAL INSTRUMENTS Filed April 10, 19:51?

mfw

INVENTI'JR 77 a. HY.

FlEL.

RNEYEI Patented Sept. 27, 1932 UNITED STAT IN GMAN J. JOHNSON, OF LOS ANGELES, CALIFORNIA COMBINED MOLD AND CLAMP FOR STRINGED MUSICAL INSTRUMENTS Application filed April 10,

My invention relates to a combined mold and clamp for manufacturing stringed musical instruments of a type such as a ukulele, guitar, or instruments of somewhat similar construction.

There has been considerable interest shown trade schools and in the manual training courses of other schools in the making of stringed musical instruments and my invention has been developed, from one standpoint, to facilitate this type of manufacture, although it is to be understood that my mold and clamps could be used for the commercial production of such stringed instruments.

An object and feature of my invention is the utilization of a mold or form which is utilized in the shaping of the sides of the musical instrument. These'various parts, previously bent, are fitted in the mold, being cut to proper lengths. The various bracing blocks and linings are inserted in the sides and in the mold or form, these various parts being glued and clamped to the mold or form and allowed to set. After the glue has set sufficiently the top and lower panels of the instrument are then secured in place on the mold or form by means of upper and lower clamping rings. These clamping rings form a guide or template for properlypositioning the top and bottom panels and after gluing of these members to the sides the rings are clamped tightly together to hold the body structure of the whole instrument while the glue sets. As soon as the body structure is firmly clamped by the rings the mold or form, which is made in sections, may be removed and then immediately used for the construction of the side members of the instrument. Therefore, by my arrangement having a separable mold or form for the side construction and clamping rings to secure the upper and lower panels it is not necessary to leave the complete mold and clamps on the body of the instrument while the glue sets but the mold or form may be used while the clamping rings are holding the body structure for the glue to set.

y invention is illustrated in connection with the accompanying drawing, in which:

Fig. 1 is a plan. partly broken away of the sections of the mold or 1931. Serial No. 529,119.

combined mold with the clamping rings, such View being taken in the direction of the arrowlofFig.2; j v

Fig. 2 is a side elevation partly broken away taken in the direction of'the arrow 2 of Fig. 1;

Fig. 3 is a transverse section on the line 33' of Fig. 1 in the direction of the arrows; Fig. 4 is a detail diagram similar to Fig. 3 showing the sectional mold or form in position, retaining the side wall structure of the instrument Fig. 5 is a sectional View similar to Fig. 3, showing the clamping rings retaining the body structure in a clamp;

Dealing first with the mold or form designated generally by the numeral 11, this comprises two distinct sections 12 which have a wall structure 13 with a central ing rib 14. At the neck of the instrument there is a substantial neck block 15 and at the opposite end there is a tail block 16. These blocks have a joint or split 1'5 and each is provided with a clamping block 15 is provided with saw kerfs 19 for the insertion of a small saw of a keyhole type to be used in the further manufacture of the instrument.

The mold forms have an inside surface 20 which is shaped to confine the of the instrument body, these wood having end joints 22.

wood are of the side walls 21 being made of The strips of requisite width to form the side walls of the instrument and are usually supplied slightly longer than necessary so that the constructor can saw these on to the desired length. At each end'there are fitted blocks 23 and 24, and upper andlower linings and 26are also fitted in position, these being glued, and such parts are secured to the mold or form 11 by using a C-shaped or other ordinary wood workers" clamps. The wall structure with the blocks 23 and. 24: and the linings 25 and 26 remain in this form until the glue has obtained a set. Then a sawofa keyhole type may be inserted in the kerfs 19, which, it will be noted from Fig. 3, converge downwardly, and then a cut may be madethrough the side strengthenbolt 18 to clamp the; form together. The

these being'glued in place,-

' to which is through wall 21 of the instrument body at the points indicated at 27 (Fig. 1). This is for the purpose of cutting the outer wall for attaching the neck of the instrument.

A characteristic of the clamping sections 12 is that on the sides these are provided with a plurality of vertical grooves 28, the side wall of the mold having a slight outward bulge 29 to accommodate such grooves. In each of the blocks 16 there is also a vertical groove 30, this being,,in effect, a notchin each of the joining faces at the junction line 17 eX- tending from the inside surface 20.

After the side walls with the blocks and the lining pieces have set sufficiently, the

wood working clamps used for holding these parts in proper position in the mold or form 11 are removed and a lower clamping ring 31 formed in one piece is placed on a work table. This clamping ring has a flat upper surface 32, and a series of bolts or studs 33 extend upwardly therefrom, these being threaded at the top. Then, on this lower ring there is placed the bottom panel 34 of the instrument body, this panel being shaped to conform to the shape of the side walls of the instrument, and in fitting this the bolts 33 act as a template or jig. The mold or form 11 with the sides of the instrument clamped therein is then placed on the lower ring 31, the bolts 33 passing through the grooves 28 and 30. Then the lower edge of the instrument sides are properly seated the upper panel .35 is placed on the upper edge of the side walls of the instrument and an upper clamping ring 36 is secured in place. In this operation the bolts 33 again function as a jig or template. The upper ring 36 has a series of perforations 37 through which the bolts 33 i extend and then wing nuts 38 are tightly secured in position, these being clamped down after the glue has been applied to the wooden structure of the instrument body which are to be glued together. As soon as these parts have been properly adjusted and the nuts 38 tightened there is no further necessity of leaving the mold or form 11 in position and the bolts 18 are loosened, these extending through the blocks 15 and 16, and the two elements 12 of the mold or form are removed in a direct lateral motion, these being pulled away from the bolts 33 on account of such bolts passing through grooves, the entrance the inner face of these mold or form members. This leaves the body structure secured between the upper and lower clamp rings as illustrated in Fig. 5 and they may be left a sufficient time for the glue to set. It is usual in the instrument at the upper and lower panels to have transverse supporting braces 39 formed of wood which are glued to the upper and lower anels. These are secured in position prior tov the attachment of the lower and upper panels.

being removable by Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. In a device as described, a mold for musical instruments having a neck and a tail portion with two side pieces connecting said portions, the neck and the tail pieces having longitudinally split joints secured together by bolts, said mold being adapted for holding and retaining the sides of a musical instrument clamped therein while gluing, and said mold having vertical slot-s or grooves on its inner surface adapted to receive vertical bolts.

2. In a device as claimed in claim 1, a lower ring and an upper ring adapted to clamp the lower and upper panels of the instrument to the form, bolts connecting said rings extending through the slots in the mold.

3, A device as described, comprising in combination, a mold for the sides of a musical instrument, having a neck and a tail portion with opposite sides connecting said portions, the neck and the tail-portions having eacha longitudinal joint, the joints being in alignment with bolts to secure the neck and tail portions together at said joints, the side parts of the mold each having vertical slots or vertical grooves on their inner surfaces, the mold being adapted to hold and retain the sides of theinstrument while being glued, and lower and upper clamping rings adapted to clamp the lower and upper panels of the instrument to the mold, bolts extending through the rings and said grooves, said mold being removable by disconnecting the bolts through the neck and the ;ail portions and withdrawing the sides laterally, thereby leaving the musical instrument clamped between the rings.

4. A device as described, comprising a mold having a. neck and a tail block with sides connecting said blocks, each block having a longitudinal vertical joint with bolts securing the portions of the blocks together at the j oint,said mold being adapted to receive and retain the sides of a musical instrument clamped therein while being glued, the sides being curved to conform to the curvature of the sides of the instrument, the mold having vertical grooves on the side portions from the inside of the mold, and a vertical groove at one of the vertical joints, a lower clamping ring having bolts secured. thereto, the bolts extending vertically through said grooves, an upper clamping ring secured to the bolts, the clamping rings being adapted to clamp lower and upper panels to the sides of the musical instrument while being glued, and said mold disconnecting the bolts through the neck and the tail blocks and withdrawing parts of the mold laterally away from said bolts and from the sides of the instrument.

v gitudinal vertical 5. A device as described, comprising a mold having a neck and a tail block with sides connecting said blocks, each block having a lonjoint with bolts securing blocks together at the oint, said mold being adapted to receive and retain the sides of a musical instrument clamped therein while being glued, the sides being curved to conform to the curvature of the sides of the instrument, the neck block of the mold having saw kerfs therein for insertion of a saw to cut the sides of the instrument while retained in the mold.

the portions of the 6. A device as'described, comprising in combination, a mold having a neck anda tail block with sides connecting said blocks, the sides conforming to the shape of the sides of the musical instrument, said blocks having each a longitudinal vertical joint, said joints being in alignment with bolts throughthe blocks at the joints to secure the mold together, the mold being thereby formed in two parts, said mold being adapted to receive and retain the sides and end blocks of the instrument while such sides and blocks are being glued, the mold having vertical grooves in its side walls from the interior of the mold, and a vertical groove at the joint in the tail block, the neck block having saw kerfs for insertion of a saw and adapted for. cutting through the side of the instrument.

7. A device as claimed in claim 6, a lower ring having a series of vertical bolts, said bolts being adapted for insertion vertically.

through the grooves in the mold, an upper ring secured to said bolts, the bolts forming a template for centering the lower and upper panels of the instrument, such panels being clamped between the rings, said rings being adapted to retain the sides and panels of the instrument while being glued after removal of the sides of the mold.

8. In a device as described, a lower ring having a series of bolts secured thereto, an upper ring having perforations to receive said bolts, said bolts forming a template for centering the lower and upper panels of a musical instrument, the sides of the instrument being positioned in the inside of said bolts, the rings being adapted to attach the lower and upper panels of the musical instrument to the sides.

In testimony whereof I have signed my name to this specification.

INGMAN J. JOHNSON. 

